1. Field of the Invention
The present invention generally relates to a semiconductor processing apparatus, and particularly to a cluster type semiconductor processing apparatus having a relatively small footprint.
2. Description of the Related Art
The number of wafers processed per unit time on a semiconductor manufacturing apparatus (i.e., throughput) has been a major concern in semiconductor production in recent years. One way to improve this throughput is to increase the number of processing chambers attached to the semiconductor manufacturing apparatus and allow for parallel processing using these chambers, thereby increasing the number of wafers processed.
However, increasing the number of processing chambers will increase the floor area occupied by the apparatus (i.e., footprint) as long as the processing chambers are arranged horizontally on the same plane. In a limited space, this will reduce the number of apparatuses that can be installed. If the processing chambers are stacked vertically on top of each other, maintainability will decrease.